MEASUREMENT OF PHYSIOCHEMICAL PARAMETERS AND DETERMINATION OF THE LEVEL OF RADIOLOGICAL THREAT TO THE POPULATION ASSOCIATED WITH THE KARNAPHULI RIVER SEDIMENT CONTAINING MUNICIPAL AND INDUSTRIAL WASTES OF CHITTAGONG CITY IN BANGLADESH

摘要

The research work has been aimed to assess the radiological and chemical threat caused due to urban and industrial wastage drainage to the inhabitants of the Chittagong city in Bangladesh. For finding the chemical effects along with the measurement of radiological threat, the physiochemical characteristics (temperature, pH value and oxidation-reduction potential) of the sediment samples have been analysed. The activity concentrations of naturally occurring radionuclides ~(238)U,~(232) Th, ~(226)Ra and ~(40)K in the investigated samples have been found to be higher than those of the world average values. The artificial radio-nuclide ~(137)Cs in the samples studied has not been detected. The mean value of the radium equivalent activity and outdoor exposure rate in the study region have been found to be 240.94 ± 23.12 Bq kg~(-1) and 115.82 ± 10.81 nGy h~(1-), respectively. The radiation doses have been measured directly by employing beta-gamma survey meter (model: LUDLUM 44-9) from where the samples have been collected. The average values of the radiological parameters have been calculated from the activity concentrations of the radionuclides mentioned in the sediment samples found to be higher than those of the corresponding world average values.